Internal combustion engine



April 25, 1939. APP 2,155,775

INTERNAL COMBUSTION ENGINE Filed May 15, 1935 3 Sheets-Sheet l I mvENTORI ATTORNEY April 25, s pp INTERNAL COMBUSTION ENGINE s She'et s -Sheet 2Filed May 13. 19 35 INVENTOR ATTORNEY AprilZS, 1939. J. SAPP INTERNALCOMBUSTION ENGINE Filed May 13, 19:55

3 Sheets-Sheet.3

BY wayzwi afi ATTORNEYS Patented Apr. 25, 1939 UNITED STATES PATENTOFFICE John Sapp, Application May 13,

3 Claims.

This invention relates to internal combustion engines and has for anobject to provide an improved rotary combustion engine in which therotor is provided with cam surfaces which cooperate with spring pressedabutments to form air compression chambers which supply air toautomatically open the fuel valve and supply the -proper mixture of fueland compressed air to the compression chamber in which the cornbustiblecharge is fired at a point in the cycle of the motor.

A further object is to provide a rotary engine in which the fuel valvewill be opened against the tension of its spring by compressed air in areservoir disposed outwardly from the valve, opening of the valveadmitting fuel and air to the chamber in which the charge is fired.

A further object is to provide a. rotary engine in which the abutmentsand the stator will be formed with fingers adapted to interdigitate whenthe abutments are pressed back into their pockets in the rotor andprovide smooth passages of the packing bars past the abutments.

- With the above and other objects in view the invention consists ofcertain novel details of construction and combinations of partshereinafter fully described and claimed, it being understood thatvarious modifications may be resorted to within the scope of theappended claims without departing from the spirit or sacrificing any ofthe advantages of the invention.

In the accompanying drawings forming part of this specification,

Figure 1 is a longitudinal sectional view of an internal combustionengine constructed in accordance with the invention.

Figure 2 is a cross sectional view taken onthe line 2-2 of Figure 1.

Figure 3 is a detail sectional view taken on the line 3--3 of Figure 2.

Figure 4 is a detail sectional view taken on the line 4- -4 of Figure 5and showing the packing bars and packing rings, parts being shown inelevation.

Figure 5 is a cross sectional view taken onthe line 5-5 of Figure 4.

Figure 6 is a detail perspective view showing the fingers of the stator.

Figure 7 is a. diagrammatic view showing both engines spaced apart onthe shaft and showing the passages leading to both engines as pipes,also showing the relationship of the air compressorand its pipes, andthe fuel pump and its pipes to each other and to both engines.

Figure 8 is a. detail perspective view showing Republic, Pa.

1935, Serial No. 21,287

the interdigitating teeth of the stator and abutments. r

Briefly the engine comprises two companion engines including respectivestators and rotors, the latter being fixed to a common shaft. Atdiametrically opposite points in the engines respective fuel admissionvalves admit fuel to compression chambers in succession, for firing. Theexplosion takes place four times a revolution, and both engines firesimultaneously at points 180 degrees apart. Each rotor has fourcompression chambers and three of the chambers in one rotor and one ofthe chambers in the other rotor supply highly compressed airsimultaneously to the chamber in which the explosion is to occur. Airpipes connect the air inlet ports ofthe chambers in parallel and air isinitially sup-. plied to the pipes by an air compressor such as ablower. The air compressed in the chambers is directed to the chamber inwhich the charge is to be fired. The initial compression chamber of eachmotor compresses" air to be delivered to the firing chamber of theopposite motor. The other compression chambers of the motor areconnected in parallel and supply compressed air for the firing chamberof the motor.

In thevarlous views the two engines are shown as duplicates of eachother and hence corresponding parts of both'engines are given identical.reference numerals to avoid confusion.

Referring to the drawings, I0 designates the stator and I I the rotor ofeach engine. The stator includes a cylindrical wall l2 and parallel sidewalls/I3, all of which walls are providedwith water jackets l4through'which water may be circulated in any suitable manner.

The rotor II is arranged in concentric relation to the stator andincludes a hub IS, a relatively heavy annular rim l6, and a web I!conmeeting the rim and the hub. The hub has keyed thereto, as shown atl8, a shaft I! which is. journaled in bearings 20 carried by the sidewalls of the stator. Referring now to Figures 1 and 'I itwill be seenthat the rotor is equipped on its periphery with eccentric cam surfaces2 I, which terminate in stepped end walls 22 and coast with the innersurface of the stator in forming a plurality of tapered compressionchambers. Disposed radially in the stator are spring pressed abutments23,24, 25 and 26, arranged at a quadrant advance from each other, whichenter the .compression chamber and bear upon the eccentric surfaces 2|thereof. Inlet ports 21, 28 and 29 are formed in the stator in rear ofthe respective abutments 23, 24 and 25, and through these portscompressed air is supplied to the chambers. pipes 3|, 32, 33 and 34 areutilized for this purpose. The outlet ports. 35, 36 and 31 of thechambers are arranged on the front sides of the abutments. By front ismeant in a direction measured in the direction of rotation of the rotor.

By referring to Figures 3 and '7 it will be see that channels 38are'formed in the stators of both motors and these channels delivercompressed air from the initial compression chamber A direct to the airreservoir 39 in the stator of the opposite motor, the reservoir beinglocated in a suitable housing 52. Compressed air from the chambers B andC is delivered directly to the reservoir 33 in the same motor in whichthey are located, through the medium of channels 31, which connect thesechambers in parallel. All of the channels are provided with check valves40.

The compressed air in the reservoir 39 automatically opens the fuelvalve 40 and supplies compressed air for the combustible charge. Thefuel valve 40 seals a port 4| through which fuel is supplied underpressure from a pump 42 .connected to the port by a pipe 43. The valvealso seals a port 44 which communicates with the reservoir 39. A helicalcompression spring 45 is mounted on the stem of the valve and is held inplace by a plug 36. The spring holds the valve closed until sufficientpressure is built up in the reservoir to overcome the tension of thespring and permit the valve to open.

After the combustible charge is supplied to th particular chamber inposition to be fired, the charge is ignited through the medium of aspark plug 41 or may be fired by the high temperature generated by thecompression of the air as in a Diesel engine. During the explosion orpower impulses, which take place in both engines at the same moment, thevalves 40 are held closed since the pressure of the burning gases isgreater than the air pressure in the reservoir and this excess pressureholds the valve closed.

During expansion of the gases the rotor is advanced and the gasesexhaust through a port 48. The exhaust port 48 for spent gases islocated in front of the abutment 23 of the initial compression chamberA.

The abutments 23, 24 and 25 are mounted in housings 49 carried by thestator and are spring pressed inwardly against the rotor by helicalcompression springs 50 confined under tension between the outer ends ofthe abutments and the inner walls of their housings. The abutment 26however is not mounted in an individual housing but is slidably fittedon the face of an abutment 5| which is mounted in a housing 52 carriedby the stator, and a second abutment 53 is mounted in the same housing,and both of the abutments 5| and 53 are spring pressed inwardly byhelical compression springs 54 confined under tension between the outerends of the abutments and the inner wall of the housing 52. Theabutments 5| and 53 are independent of each other and tend to preventloss of compression from the combustible chamber since one of theseabutments is in contact with the rotor surface while the other isdescending the rotor steps.

The abutment 26 is urged radially by a helical compression spring 55which is confined under tension between the outer end of the abutmentand a lug 56 formed on the abutment 5|. abutment 26 performs the samefunction as the An air compressor, such as a blower, and.

The

abutments 24 and 25, that is, it prevents leakage of the air beingcompressed in the respective chamber. The two abutments 5| and 53 definea rigid wall of the combustion chamber.

As best shown in Figures 2and 6 the compression abutments 24, 25 and 26are provided at their inner ends with forwardly extending taperedfingers 55' as best shown in Figures 2 and 8. The compression abutments24, 25 and 26 are provided at the inner end with forwardly extendingtapered fingers 55 which are set at an oblique angle to the face of theabutment. These fingers interdigitate with similarly constructed fingers56 carried by the inner surface of the stator. When the abutments arepressed back against the tension of their controlling springs by the camsurfaces of the stator, the interdigitating fingers on the abutmentspromote smooth passage of the packing bar 60 hereinafter described.

The fingers being disposed diagonally as shown in Figure 2, promoteuniform wear on the packing bars instead of forming grooves in thepacking bars as would be the case were the fingers disposed parallelwith the rim of the rotor, to prevent leakage between the sides of thestator and the rotor packing rings 51 of the general shape shown inFigure 5 are employed. These rings are housed in seats 58 in the rotorand spring pressed outwardly against the stator by springs 59 disposedin the seats behind the rings. To prevent leakage between the innersurface of the stator and the peripheral surface of the rotor bars 60are provided, best shown in Figure 4, these bars being loosely fitted intransverse seats 6| formed in the rotor. Preferably a pair of bars aremounted in each seat and spring pressed apart through the medium of ahelical compression spring 62.

In operation there are four impulses during each revolution ofeachmotor. The explosions take place in the compression chambers insuccession. One of the four chambers is always firing while the threeother chambers are compressing air. Two of the three chambers aredelivering air in parallel to the reservoir of the respective motorwhile the other one of the three chambers is delivering compressed airto the reservoir of the opposite motor. The combustible charges arefired by the spark plug 41 simultaneously to rotate the rotors in ,thedirection of the arrow. Burnt gases from an explosion are simultaneouslyexhausted through the exhaust ports 48 while air is being compressed bythe remaining compartments for delivery into the reservoirs, the valvesof which are heldclosed by the pressure of the fired mixture.

The reason why the initial compression chamber of each motor deliversits supply into the reservoir of the other motor is that the outletchannel 38 of the compression chamber is di-' rectly opposite thereservoir 39 of the opposite motor.

From the above description it is thought that the construction andoperation of the invention will be fully understood without furtherexplanation.

What is claimed is:

1. In a rotary internal combustion engine, a stator forming acylindrical enclosure, a'shaft rotatably and concentrically mountedwithin said stator, a. rotor fixed on said shaft, said rotor havinguniformly spaced cam surfaces providing with the cylindrical wall of;said stator a corresponding number of arcuate tapered compression andexplosion chambers, uniformly spaced abutments carried by said stator,each abutment belng slidable radially of said stator and spring pressedinto sliding engagement with said rotor, there being an air inlet portimmediately in rear of each abutment, a fuel port in the statorsupplying combustible mixture to the chambers in succession, a reservoirin the stator having a passage communicating with the fuel port, a

opening, and means connecting the remaining ones .of the last namedopenings in parallel to said reservoir.

2. In a rotary internal combustion engine, a stator forming acylindrical enclosure, a shaft rotatably and concentrically mountedwithin the stator, rotors fixedly mounted on said shaft,each rotorhaving uniformly spaced cam surfaces providing with the cylindrical wallof said stator a corresponding number of arcuate tapered compression andexplosion chambers uniformly spaced apart, abutments carried by saidstator uniformly spaced apart, each abutment being slidable radially ofsaid stator and spring pressed into sliding engagement with a respectiverotor, there being an air inlet port in the stator immediately in rearof each abutment, a fuel port in the stator for supplying a combustiblemixture to the chambers of a respective rotor in succession, a fuelreservoir in the stator for each rotor having a passage communicatingwith the fuel port, a. spring pressed valve controlling the passage,means connecting the air inletports in parallel to a source ofcompressed air, there being openings in said stator immediately in frontof each abutment, one of said openings next forwardly of said fuel portbeing an exhaust opening, the other ones of said openings beingcompressed air openings, means connecting the initial one of saidcompressed air openings next forwardly of the exhaust opening for arespective rotor to the fuel reservoir of the opposite rotor, and meansconnecting the remaining ones of said openings in parallel to thereservoir of the respective rotor.

/3. In a rotary internal combustion engine, a stator, a plurality ofradially extending spring pressed abutments carried by the stator, arotor having a plurality of spaced arcuate tapered chambers havingexternally disposed curved walls formed in the periphery receiving saidabutments, means for admitting and firing a charge in one of thechambers, compression passages connecting one end of each of the otherchambers with said means, means for connecting said passages to asourceof compressed air, packing bars on the periphery of the rotor,spaced fingers carried by the abutments and arranged to engage the innerface of the stator, and spaced fingers carried by the stator adapted tointerdigitate with the abutmentfingers for promoting smooth passing ofthe packing bars past the abutment.

a JOHNSAPP.

